He faces five remaining charges, including that he received, transported and distributed child pornography, and that he molested a boy in 2003 at the former Brooks AFB in San Antonio, now known as Brooks City-Base.

Those alleged incidents occurred before Olson moved to San Antonio in late 2002, and he has not been charged in any of them, but admitted to them in a written statement introduced in his case here.

In the statement, Olson minimized the alleged assaults and said his acts did not continue at any of the hospitals he's worked for in Texas.

Olson told agents he didn't have unfettered access to children at the San Antonio hospitals.

“I have never done it since 2003 because I have not had the opportunity,” Baker said, reading from Olson's written statement.

Olson had worked at Methodist Hospital five years when he was arrested. He also briefly worked at Northeast Baptist Hospital before that.

Both hospitals said in statements that all appropriate background checks were done on Olson, that nothing turned up that would have prevented his hiring, and that their top concern is the well-being of patients and their families.

Baker said agents seized Olson's computer and a hard drive as part of the probe, which began in Buffalo, N.Y. He said the FBI found Olson was making child porn available for trading on a peer-to-peer Web site, and communicating with others with similar interests.

Under questioning, Olson told agents the devices may have more than 1 million child-porn images, Baker said.